Ruberythric acid

Description

Yellow, needle crystals. Ruberythric acid is one of the natural colorants extracted from madder roots. It decomposes to form alizarin in boiling water. The brilliant red color is usually mordanted with potassium, barium, or calcium salts.

Synonyms and Related Terms

ácido ruberítrico (Port.); rubian; ruberythrinic acid; rubianic acid

Risks

• NIH: Info page

Physical and Chemical Properties

Soluble in hot water. Slightly soluble in cold water, ethanol. Decomposes in acids and alkalis.

Composition	C25H26O13
Melting Point	258-261 C
Molecular Weight	mol. wt. = 534.47

Resources and Citations

• Artists' Pigments: A Handbook of their History and Characteristics, Elisabeth West FitzHugh, Oxford University Press, Oxford, Vol. 3, 1997 Comment: H.Schweppe, J.Winter, "Madder and Alizarin"